JENA, Germany—The dream of manufacturing office-and apartment-size lamps that imitate the light of a blue sky—inside windowless rooms—is likely to become reality in the next year or so, thanks in part to researchers at the Fraunhofer Institute for Applied Optics and Precision Engineering (aka “the Fraunhofer IOF”) here, the Fraunhofer IOF’s Kevin Füchsel said. One big thing will be to miniaturize LED-based lighting that already accomplishes this on a large scale, and the researchers are applying their expertise in micro-optical element design and fabrication.
To make a micro projector, the Fraunhofer IOF engineers employed CAD, put the design into an automation tool and watched a 3D inkjet printer fabricate the micro optical lenses. Then they employed automation to assemble the optics with light sources.
“You can imagine there is a glass sheet, and you print your tiny lenses on top of the glass substrate with ink jet printing, lens by lens. That’s called a micro-optical element,” Füchsel said. “It’s a really complicated process to fabricate this. So we decided to use 3D printing technology to develop a really nice process: automated fabrication of micro-optical elements.”
Without automation and additive manufacturing (AM), it wouldn’t be possible to produce a lamp that would be affordable and fit in an office or a home on a cost-efficient basis, he said. Humans simply lack the dexterity needed to make micro-optical lenses.
The structure of the smaller blue sky-imitating lamp includes a multi-aperture micro-optical array approach to realize a telescope array with minimum thickness. In the end, the lamp produces the sort of anxiety-reducing light that would be welcome in homes and medical imaging companies—because it gives the impression of having sunlight from the outside.
“One outstanding project is a cooperation with the innovative Italian company CoeLux,” Füchsel said. “Ideas from them and the researchers at Fraunhofer IOF come together and made a new miniaturized product that has a direct light source that imitates the sun and gives you the impression you are outside.”
CoeLux is already selling a large version of the lamp. But, at cubic-meter scale, “you need additional space to install it, and most people don’t have that,” Füchsel said.